1. Field of the Invention
The present invention pertains to active centrifugal separator systems for separating entrained gas from liquids, particularly useful in metering crude oil production.
2. Background
In the production of crude oil, and the processing of certain other gassy liquids, it is necessary or at least desirable to perform separation processes to separate the gas from the liquid phase of the mixture. Such processes are usually carried out to retain the gas for other uses and to more accurately determine the flow rate and composition of the liquid flowstream. Such processes are particularly useful in the production of crude oil whereby separation of the liquid phase from the gas phase is important for further handling and for accurate measurement of production from each well or a group of wells.
U.S. Pat. No. 4,852,395 to Miroslav M. Kolpak and assigned to the assignee of the present invention describes a flow measuring system of a type particularly suited for measuring crude oil production. This patent describes one type of a so-called "passive" centrifugal separator wherein a gassy liquid flowstream is conducted into a separator vessel through a tangential inlet conduit and centrifugal flow is induced to effect separation of a substantial amount of gas from the liquid phase. The system described in the '395 patent does, however, require the use of a device for measuring the residual gas content of the liquid flowstream to more accurately gauge the flow rate and composition of the liquid.
An alternate approach is to more thoroughly separate the gas phase from the liquid phase prior to liquid flow measurement and measurement of the water content of the liquid phase. The present invention is directed to several embodiments of a system which provides improved gas-liquid separator devices, particularly adapted for measuring the flow rate of gas-liquid flowstreams encountered in production of crude oil and the like.